The Propagation of Light

In what substance in Table 1.1 light is the speed of \(2.290 \times 10^{8} \mathrm{~m} / \mathrm{s} ?\)?

Text Transcription:

2.290 times 10^8 m/s

Day 12 2/1/2016 Topics for Midterm fluids of all kinds, not differential equations harmonic oscillator, up to damping simple harmonic motion some problems with damping and resonance after exam Read 15.1, 15.2, 15.4 Waves y(x, t) = Asin(kx wt) displacement amplitude of displacement t = 0 y(x, t) = Asin(kx) x = 0 y(x=0, t) = Asin(wt) = Asin(wt) y(x, t=0) = y(x + λ, t=0) Asin(kx) = Asin[k(x+λ)] kλ = 2π 2π The wave number k = γ Asin(wt) = Asin[w(t+T)] wT = 2π → w = 2π = rad angular frequency T s frequency f → f = T1 Ex. vw= 0.5 cm/s A = 1cm T = 8s λ = 4cm k = π rad ω = 2π = π rad 2 cm T 4 cm y(x, t) = 1 cm sin ( π rax − π rat) 2 cm 4 s verify, does 4(x = 0, t = 0) = graphs says no! Initial Phase Phase φ = kx − ωt y(x,t) = Asin(φ + φ )o π π π sin(kx ωt+ )2= sin(φ)cos( ) + c2s(φ)sin( ) 2 Ex. y(x, t) = Asin(kx wt) = Asin(x t)k = 1, w = 1 t = 0 y(x, 0) = Asinx t = π y(x, ) = Asin(x ) = Asinxcos( ) Acosxsin( ) π 2 2 2 2 2 y(x, ) = Acosx 2 y = Asin(kx wt)